Detent mechanism for a cabinet having a pull-out drawer

ABSTRACT

A cabinet is provided having at least one pull-out drawer which is slidably mounted therein on a linear ball-bearing assembly. The drawer is releasably held in its extended or pulled out position by a leaf spring carried by the ball-bearing cage of the ball-bearing assembly in cooperation with a protrusion in the stationary guide member of the ball-bearing assembly, which form a detent mechanism entirely independent of the ball bearings.

United StateS Patent Abbate, Jr. et al. 1 1 Apr. 25, 1972 [s41 DETENT MECHANISM FOR A CABINET 2,097,430 11/1937 Visser ..312/333 x HAVING A PULL-OUT DRAWER 2,661,997 12/1953 Wilmer.... 721 Inventors: Ronald A. Abbate, Jr., Glen Head; Stewart 28%? g 312/333 3 o99's01 7/1963 113355251 IIIIIIIIIIIIIIIII 312/348 x [73] Assignee: International Playtex Corporation, New

York, NY. Primary Examiner-James T. McCall [22] Filed: Nov. 10 1970 Attorney-Stewart J. Fried and Jeffrey A. Schwab [2]] App]. No.: 88,440 [57] ABSTRACT A cabinet is provided having at least one pull-out drawer U.S. whi h i mounted therein on a linear ball-bearing as. [51 Int. Cl. ..A47b 88/00 The drawer is releasably l in i extended or pulled 58] Field of Search ..3 1 2/333, 341, 343, 344, 35 out i i b a leafspring carried by the ball-bearing cage of 3 308/35 the ball-bearing assembly in cooperation with a protrusion in the stationary guide member of the ball-bearing assembly, [56] References Cite-d which form a detent mechanism entirely independent of the UNITED STATES PATENTS bearmgs- 3,471,209 10/1969 Howard ..3l2/333 X 5 Claims, 5 Drawing Figures PATENTEUAPR 25 1972 3. 658, 398

RONALD A. ABBATE, Jr. I Y STEWART J. FRIED PATENTEDAPR 25 I972 3.658, 398

- 42 lnwan'mns RONALD A. ABBATE, Jr- STEWART J. FRIED BACKGROUND OF THE INVENTION This invention relates to a detent mechanism for a cabinet having a pull-out drawer which is releasably held in its extended position, and when released automatically returns into the cabinet.

One common form of support and guide means for a pullout drawer of a cabinet is a linear ball-bearing assembly. The linear ball-bearing assembly is comprised of a stationary guide member'attached to the cabinet, and a slide member attached to the underside of the drawer which is slidably disposed within the stationary guide member by means of ball bearings housed in a sliding ball cage. The stationary and slide members form channel-like tracks in which the ball bearings are positioned and move linearly therein when the drawer is pulled out. On pulling the drawer from the cabinet, the sliding ball cage and slide member, as well as the drawer attached to the slide member, follow a linear logitudinal path defined by the tracks in the stationary guide member. The stationary guide member may be secured to the cabinet at an angle which is upwardly inclined towards the front of the cabinet, such that return of the opened drawer is effected by gravity.

In view of the automatic gravity return of the pull-out drawer from its outermost excursion position it has been found desirable to provide a stop and retention mechanism to maintain the drawer at an outward position so that the contents of the drawer may be examined and/or removed.

Especially where the cabinet and drawer assembly is to be employed as a merchandize display and service unit, both the setting and release of the stop and retention mechanism should be actuatable and releasable by a simple action or motion by the user without complex setting and releasing arrangements.

In the prior art there is provided a detent mechanism for this purpose in the form of a ball receiving recess in one of the channel-like tracks which is resiliently urged toward the op posed track side so that the recess catches one of the ball bearings on extension to hold the drawer until it is returned to its initial position by external pressure being exerted on the drawer to urge the ball bearing outward of the recess. This structure requires a certain amount of play or resiliency between the various elements of the linear ball bearing assembly. The requisite play also presents the possibility of dislodging the ball bearing with the application of too much force in pulling out the drawer. Further, the dual function of the ball bearing (e.g., to guide movement and serve as detent) does not permit an independent adjustment of each function. That is, in view of the gravity return, the weight of the contents of the drawer acts against the holding force of the stop and retention mechanism with'the degree of detent holding force required being a function of the angle of inclination and the weight of the drawer and its contents. The prior art ball bearing detent with its limited degree of adjustment provides little latitude for varying the detent holding force.

Accordingly, one of the objects of the present invention is 'to provide a cabinet having a detent mechanism for a pull-out drawer which is independent of and does not require the ball bearing as an action part of a detent mechanism, and which does not rely on any play in the ball bearing assembly.

It is another object of this invention to provide a detent mechanism in which the force required for releasably holding the drawer in extended position may be varied in accordance with the requirements of any particular application.

SUMMARY OF THE INVENTION In carrying out this invention in one illustrative embodiment thereof, a cabinet is provided having at least one inclined pullout drawer which is slidably. mounted therein by means of a linear ball-bearing assembly, and releasably held in its extended position until released by a detent means comprising a leaf spring and cooperating protrusion which is independent of the ball bearings in the ball-bearing assembly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an illustrative embodiment of a cabinet in accordance with this invention, showing one drawer removed.

FIG. 2 is a cross-sectional view taken alonglines 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view taken along lines 3-3 of FIG. 1.

FIG. 4 is a cross-sectional view taken along lines 4-4 of FIG. 1 with the drawer shown in the open position.

FIG. 5 is a cross-sectional view taken along lines 5-5 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, a cabinet 10 is provided having upstanding sides 12 and 14, back 16, and a front panel 18 with a plurality of upwardly inclined pull-out drawers 20 mounted therein. The cabinet 10 illustrated is a form of a merchandise display cabinet, but it will be appreciated that the invention is not considered limited to the particular form of design shown. Three pull-out drawers 20 are shown as generally open type shelves, but it will be appreciated that other combinations of shelves and drawers may be employed, as desired, as long as the cabinet 10 is provided with at least one pull-out drawer 20 which is slidably mounted in the cabinet and releasably held in its extended position until released in accordance with this invention. Further, the term drawer, as used herein, is intended to include both generally open and closed wall slidably mounted compartments.

The pull-out drawer 20 includes a bottom 22 and an end wall 24 which is adapted to house a quantity of merchandise 25 which is to be displayed, stored and selected therefrom.

The pull-out drawer 20 is slidably mounted in the cabinet 10 by a pair of linear ball-bearing assemblies 30 which facilitate movement of the drawer into and out of the cabinet (with only one assembly 30 for each shelf illustrated). Each of the ballbearing assemblies30 includes a stationary U-shaped guide member 34, a movable U-shaped slide member 40, and a intermediate U-shaped ball-bearing cage 48. The ball-bearing cage 48 has upstanding leg members 52 and 54 which have recesses 51 therein for carrying a plurality of rollable ball bearings 50 therein. The stationary guide member 34 is suitably mounted to the side wall 12 of the cabinet 10 as by bracket 32. The stationary guide member 34 has upstanding legs 36 and 38 which are curved at 37 (FIG. 3) to form the exterior race or channel-like track for the ball bearings 50. The slide member 40 is mounted along the bottom 22 of the pullout drawer20 by fastening members 41. The slide member 40 has downward extending legs 42 and 44 which are curved at 43 (FIG. 3) to form the inner race or channel-like track for the ball bearings 50. Accordingly, the curvatures 37, 43 of the opposed legs 36, 42 and 44, 38 form races or tracks for the ball bearings 50. This conventional ball-bearing assembly 30 allows the slide 40,'as well as the ball-bearing cage 48, which moves at a considerably slower rate than the slide 40, to move linearly and longitudinally along the guide member 34 which remains fixed, as the drawer 20 is pulled out and returned into the cabinet.

As will be seen in FIG. 2, the stationary guide member 34, and accordingly the ball-bearing assembly 30 and drawer 20 is mounted to the cabinet side 12 by bracket 32 at an angle which is upwardly inclined towards the front of the cabinet.

. This angle is selected to allow the pulled-out drawer 20, when released from its open position to automatically return to its closed position in the cabinet by force of gravity. Mounted on the back end of stationary guide member 34 on pin 31 is a bumper 33, which may be formed of hardened rubber. A spiral spring 39 is mounted on the cabinet back 16 in a position adapted to contact the back side 24 of the drawer 20. When the drawer is returned to its rest position, the slide member 40 strikes the bumper 33 and the back side 24 of the drawer- 20 contacts the spring 39, the combination of which absorbs the shock of the returning drawer 20 to its closed position.

So as to prevent the ball bearings 50, interlinked ball cage 48 and slide member 40 from sliding completely outward of the stationary member 34 the inner end of the stationary member 34 includes the aforedescribed fixed bumper 33. The other or outer end of the stationary member 34 is provided with a stop by the formation, after the loading of the ball cage 48 and slide member 40 within the stationary member 34 of an upwardly extending curved protrusion 35, (most clearly shown in FIG. 2) such as by a stamping, in the stationary member 34. The protrusion 35 projects upwardly from the base of the stationary member 34 a sufficient distance to intersect the base of the U-shaped ball cage 48 and thus block the excursion of the ball cage 48 and the interlinked slide member 40 at a predetermined point to prevent disengagement of the slide member 40 from the outer open end of the stationary member 40.

The novel detent mechanism embodied in this invention further employs such upward extending curved protrusion 35 in the stationary member 34 as a receptacle for coaction with a resilient leaf spring member 60 positioned on the ball cage 48 independent of the ball bearings 50. The leaf spring 60 is radiused downward along its end portion 62, and is held on the ball cage 48 by tabs 56 which are conveniently punched up from the underside of the ball cage 48. Tabs 46 (FIG. 4) which are projecting orthogonally outward at the back end of the slide member, as by bending the sides 44 and 42 outward and orthogonal to the slide member 40 on its rearward end further aid in seating the leaf spring 60 over the protrusion 35.

For an explanation of the operation of the novel detent mechanism reference is made to FIGS. 4 and 5, showing the drawer in open position, or fully extended, with the detent mechanism releasably holding the drawer in its extended position. When the drawer 20 is pulled outward, the ball cage 48 and the slide member 40 carrying the drawer 20 are moved linearly along the guide member 34. The extent of the drawers excursion is fixed by the upward curved protrusion 35 which forms a stop means for the drawer. As the ball cage 48 is moved toward the protrusion 35, the radiused end portion 62 of the leaf spring 60 rides over the protrusion 35 until the front edge of the ball cage contacts the front curved portions of the protrusion 35, at which time the radius end portion 62 of the lead spring 60 firmly engages the downward slope of the rear surface of the protrusion 35. A positive and firm engagement of the leaf spring 60 with the protrusion 35 is ensured by the tabs 46 of the slide member 40. Since the ball cage carries the leaf spring 60 and since the relative positions of the ball cage within its races or tracks allows for a degree of independent movement of the ball cage with respect to the slide member 40 the possibility of non-engagement of the spring 60 is presented. However, the tabs 46 overcome this problem since the tabs 46 contact the rear of the ball cage 48 on full extension of the slide member 40 thus forcing the ball cage against the front edge of the protrusion 35 to ensure the proper seating of the radiused end portion 62 ofthe leafspring 60. The tabs 46 contact both legs of the ball cage 48 at the same time the ball cage is moved forward thus applying uniform pressure to properly seat the spring 60 on the protrusion 35.

It should be noted that the detent action which is provided does not act upon, and is independent of any capturing of the ball bearings 50. Accordingly, no reliance is made on resiliency or play between the stationary member 34, the ball cage 48, and the slide member 40, as heretofore has been required. The leaf spring detent also offers the added advantage of providing an adjustable force by the selective choice of the material curvature or thickness of the spring in accordance with the type of cabinet utilized and the weight of merchandise which it will carry.

The leaf spring 60 releasably holds the drawer 20 in its fully extended position, and is released merely by pushing the drawer inward, forcing the radius portion 62 of the spring 60 to retreat over the protrusion 35, at which point the drawer automatically returns into the cabinet, under the force of gravity due to the inclined mounting of the ball-bearing assembly in the cabinet. On return, the slide member 40 and the rear wall 24 of the drawer hit the bumper 32 and spring 39 respectively, to appropriately absorb the shock of return.

Since other modifications, varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the examples chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.

We claim:

1. A cabinet structure comprising in combination;

a cabinet having at least one pull-out drawer slidably mounted therein upwardly inclined towards the front of the cabinet;

a ball bearing assembly for slidably mounting said pull-out drawer, in said cabinet for movement of the drawer between closed and open positions, said ball bearing assembly including a stationary guide member mounted to said cabinet at an upwardly inclined angle, a slide member mounted to said drawer and positioned'in said stationary guide member and forming therewith channellike ball bearing track means, a sliding ball bearing cage ball bearing assembly having a plurality of ball bearings disposed for rollable movement therein;

said ball bearings positioned in said channel-like ball bearing track means for slidable movement of said slidable ball bearing cage therein whereby as said drawer is pulled out or released said sliding ball bearing cage and said slide member move along said stationary guide member;

the upward inclination of the drawer providing an automatic gravity return of a released open drawer toward its closed position, with said ball bearing assembly assisting such return; and

detent means comprising two cooperating members independent of said ball bearings for releasably holding said drawer at a predetermined extended position against the gravity return force acting on the drawer from which on release said drawer automatically returns to its closed position.

2. The structure set forth in claim 1 wherein said two cooperating members of said detent means comprise a stop member for preventing sliding movement of said stationary guide member beyond a predetermined point, and means for releasable engagement with said stop member, said means for releasable engagement holding said drawer in an extended position until disengaged by pushing the drawer in towards said cabinet.

3. A cabinet structure comprising in combination;

a cabinet having at least one pull-out drawer slidably mounted therein;

a ball bearing assembly for slidably mounting said pull-out drawer in said cabinet said ball bearing assembly including a stationary guide member mounted to said cabinet at an upwardly inclined angle, a slide member mounted to said drawer and positioned in said stationary guide member and forming therewith channel-like ball bearing track means, a sliding ball bearing cage ball bearing assembly having a plurality of ball bearings disposed for rollable movement therein;

said ball bearings positioned in said channel-like ball bearing track means for slidable movement of said slidable ball bearing cage therein whereby as said drawer is pulled out or released said sliding ball bearing cage and said slide member move along said stationary guide member;

the detent means comprising two cooperating members independent of said ball bearings for releasably holding said drawer at a predetermined extended position from which on release said drawer returns in said cabinet said two cooperating members of said detent means comprise a stop member for preventing sliding movement of said stationary guide member beyond a predetermined point, and means for releasable engagement with said stop member, said means for releasable engagement holding said drawer in an extended position until disengaged by pushing the drawer in towards said cabinet;

said stop member comprises an upward protrusion on the base of said stationary guide member and said releasable engagement means comprises a leaf spring mounted on said sliding ball cage which engages said protrusion when said drawer is fully extended.

4. The structure set forth in claim 3 wherein said leaf spring includes a radiused downward end which radiused end engages a portion of said upward protrusion for releasably holding said drawer in its extended position.

5. A cabinet structure comprising in combination,

a cabinet having at least one pull-out drawer mounted therein upwardly inclined towards the front of the cabinet;

a ball bearing assembly for slidably mounting said pull-out drawer in said cabinet for movement of the drawer between closed andopenv positions, said ball bearing assembly including a stationary guide member having a base mounted at an upwardly inclined angle on said cabinet and two laterally opposed legs extending vertically from said base, the upper portions of said legs recessed to form the outer races for ball bearings;

a slide member having a base mounted on the bottom of said pull-out drawer and two laterally opposed a sliding ball-bearing cage having a base and two vertically extending legs having openings therein in which ball bearings are disposed, said ball bearings being positioned between said races for longitudinal movement of said sliding ball bearing cage along said-races,

an upwardly extending protrusion positioned along a preselected area of the base of said stationary guide member for contacting the front of said sliding ball cage when said drawer is extended, thereby providing a stop means for said drawer, and

a leaf spring positioned on and projecting out from the base of said sliding ball cage which engages said protrusion when said drawer is extended for releasably holding said drawer in its extended position. 

1. A cabinet structure comprising in combination; a cabinet having at least one pull-out drawer slidably mounted therein upwardly inclined towards the front of the cabinet; a ball bearing assembly for slidably mounting said pull-out drawer, in said cabinet for movement of the drawer between closed and open positions, said ball bearing assembly including a stationary guide member mounted to said cabinet at an upwardly inclined angle, a slide member mounted to said drawer and positioned in said stationary guide member and forming therewith channel-like ball bearing track means, a sliding ball bearing cage ball bearing assembly having a plurality of ball bearings disposed for rollable movement therein; said ball bearings positioned in said channel-like ball bearing track means for slidable movement of said slidable ball bearing cage therein whereby as said drawer is pulled out or released said sliding ball bearing cage and said slide member move along said stationary guide member; the upward inclination of the drawer providing an automatic gravity return of a released open drawer toward its closed position, with said ball bearing assembly assisting such return; and detent means comprising two cooperating members independent of said ball bearings for releasably holding said drawer at a predetermined extended position against the gravity return force acting on the drawer from which on release said drawer automatically returns to its closed position.
 2. The structure set forth in claim 1 wherein said two cooperating members of said detent means comprise a stop member for preventing sliding movement of said stationary guide member beyond a predetermined point, and means for releasable engagement with said stop member, said means for releasable engagement holding said drawer in an extended position until disengaged by pushing the drawer in towards said cabinet.
 3. A cabinet structure comprising in combination; a cabinet having at least one pull-out drawer slidably mounted therein; a ball bearing assembly for slidably mounting said pull-out drawer in said cabinet said ball bearing assembly including a stationary guide member mounted to said cabinet at an upwardly inclined angle, a slide member mounted to said drawer and positioned in said stationary guide member and forming therewith channel-like ball bearing track means, a sliding ball bearing cage ball bearing assembly having a plurality of ball bearings disposed for rollable movement therein; said ball bearings positioned in said channel-like ball bearing track means for slidable movement of said slidable ball bearing cage therein whereby as said drawer is pulled out or released said sliding ball bearing cage and said slide member move along said stationary guide member; the detent means comprising two cooperating members independent of said ball bearings for releasably holding said drawer at a predetermined extended position from which on release said drawer returns in said cabinet said two cooperating members of said detent means comprise a stop member for preventing sliding movement of said stationary guide member beyond a predetermined point, and means for releasable engagement with said stop member, said means for releasable engagement holding said drawer in an extended position until disengaged by pushing the drawer in towards said cabinet; said stop member comprises an upward protrusion on the base of said stationary guide member and said releasable engagement means comprises a leaf spring mounted on said sliding ball cage which engages said protrusion when said drawer is fully extended.
 4. The structure set forth in claim 3 wherein said leaf spring includes a radiused downward end which radiused end engages a portion of said upward protrusion for releasably holding said drawer in its extended position.
 5. A cabinet structure comprising in combination, a cabinet having at least one pull-out drawer mounted therein upwardly inclined towards the front of the cabinet; a ball bearing assembly for slidably mounting said pull-out drawer in said cabinet for movement of the drawer between closed and open positions, said ball bearing assembly including a stationary guide member having a base mounted at an upwardly inclined angle on said cabinet and two laterally opposed legs extending vertically from said base, the upper portions of said legs recessed to form the outer races for ball bearings; a slide member having a base mounted on the bottom of said pull-out drawer and two laterally opposed a sliding ball-bearing cage having a base and two vertically extending legs having openings therein in which ball bearings are disposed, said ball bearings being positioned between said races for longitudinal movement of said sliding ball bearing cage along said races, an upwardly extending protrusion positioned along a preselected area of the base of said stationary guide member for contacting the front of said sliding ball cage when said drawer is extended, thereby providing a stop means for said drawer, and a leaf spring positioned on and projecting out from the base of said sliding ball cage which engages said protrusion when said drawer is extended for releasably holding said drawer in its extended position. 